System of control.



A. J. HALL.

SYSTEM OF CONTROL.

APPLICATION FILED JAN. 4. me.

Patented Apr. 1, 1919.,

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A. J HALL. SYSTEM OF CONTROL.

APPLICATION FILED JAN-4,19%.-

Patented Apr. 1, 1919'.

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UNITED STATESPATENT our-Ion.

ARTHUR J. HALL, OF WILKINSIBUBG, PENNSYLVANIA, ASSIGNOR T0 WESTINGHOUSE ELECTRIC AND MANUFACTURING COMPANY, A CORPORATION OF PENNSYLVANIA.

SYSTEM OF CONTROL.

specificationof Lett en Patented Apr. 1, 1919..

Application filed. January 4, 1916. serial no. 70,261.

To all whom it may concern I Be it known that I, ARTHUR J. HALL, a subject of the King of Great Britain, and a resident of \Vilkinsburg, in the county of Allegheny and State of Pennsylvania, have invented a new and useful Improvement in Systems of Control, of which the following is a specification. q

My invention relates to systems of control and especially to the regenerative control of a plurality of direct-current electric railway motors and the like.

In a co-pending application of RE. Hellmund, Serial No. 414,443, filed August 9,

1915, and assigned tothe lVestinghouse Electric & Manufacturing Company, is shown and described an improved commercial type of direct-current regenerative control system, and the various novel and advantageous features of the main-circuit connections are claimed therein. I

It is the object of my present invention to provide an auxiliary governing system for the main circuits that are set forth in the above-mentioned application which shall be relatively simple in arrangement and reliable in operation, and which shall effect certain automatic sequences of operation in a relatively simple and effective manner during various portions of the accelerating or regenerative period, as hereinafter more fully set forth. I

In the accompanying drawing, Figure l'is a diagrammatic view of the main circuits of the system of control that is set forth in the above mentioned co pending application; Fig. 2 is a diagrammatic view of my auxiliary governing system for theivarious motor-controlling switches that are illustrated in Fig. 1; Fig. 3 is a detailed diagrammatic view of one of the complete main-circuit switches; Fig. A to Fig. 8, inclusive, are simplified diagrammatic views corresponding to Fig.1 and showing the circuit connections for initial series acceleration, final parallel acceleration, preliminary to regeneration, parallel regeneration and series regeneration, respectively, as denoted by the accompanying legends. Y

Referring to Fig. 1, the system illustrated comprises a plurality of suitable supply-circuit conductors Trolley and Ground; a-plurality of main dynamo-electric machines having the armatures A1 and A2 and corresponding series-connected field magnet windings F1 and F2; a reversing switch RS of a familiar electrically-controlled drum type, which is shown conventionally here, for the purpose of reversing the electrical relations of the corresponding armatures and field windings; a plurality. of accelerating resistors A111, AR2 and ARE); a pluralityof main-circuit switches LS1, LS2, M2, JR, J, G, SW1 and SW2; a transition resistor RJ fora purpose to be described; a plurality of resistors R1 and R2 that are employed during regenerative operation of the system only; an automatically-operated controller PKl that is adapted to'occupy an off position a, and a plurality of operative positions 6 to g, inclusive, and that is preferably of the drum type, for manipulating various circuit connections during the accelerating period of the motors; a second similar controller PK2 that is adapted to occupy an off position a and a plurality of operative positions 5 to a, inclusive, and that is employed during regenerative operation only, chiefly in connection with the manipulation of the resistors R1 and R2; a plurality of limit switches'of a familiar type AL and RL, the former being employed during acceleration of the motors and the latter being employed during regenerative operation; a changeover switch COS of the drum type that is adapted to occupy two positions respectively marked Accfl and Reg, standing for acceleration andregeneration; respectively, an auxiliary motor-generator set or dynamotor that is employed during regenerative operation and comprises a motor armature winding M, a generator armature winding G and a subdivided field-magnet winding having sections MFa and MFb that are connected in series-circuit relation with the armature winding M; a switch FC'that is employed for field control of the motor-generator; and a plurality of relays respectively marked Series relay and Multiple relay that sevrent of the armature winding A2 and also the current that is sent through the resistor from the generator armature winding G.

The limit switch BL is placed in the circuit shown because it has been found that, if the series coil of the limit switch receives both of the currents above referred to, the rate of deceleration of the regenerating machines is much more uniform than if a liinit switch placed in the position occupied by the switch AL, for example, were used. Various tests .givingthe torque variations of the regenerating machines with a limit switch connected in the positions respectively occupied by the switches AL and EL conclusively show that the variation in the regenerative current over the range of practical operating speed employed is relatively small in the case ofthe limit switch BL, as compared with the limit switch AL. The regenerating limit BL is also provided with an auxiliary or shunt-connected actuating coil, as is more fully described in connection with the auxiliary control system of Fig. 2.

Itshould be observed that, although the auxiliary contact members of the limit switches AL and RL are disposed in seriescircuit relation, provision has been made to render only one switch operative at a time. During acceleration, the switch RL remains down, since no current traverses the circuit of its actuating coil; whereas, during regeneration, the contact members 78 of the switch AL are bridged by contact segment a of the master controller, and, consequently, the switch AL has no effect on the regenerative operation of the system. v

The operating mechanisms of the controllers PKl and PK2 are identical, each comprising a shaft 31 that is associated with the rotatable controller drum, and a pinion 32 that is attached to the upper end of the shaft 31 and is adapted to mesh with a suitable rack member 33 which has its respective ends provided with a plurality of piston members 3% and 35. The pistons 3-1 and are respectively adapted to operate within suitable cylinders 36 and .37 the access of fluid pressure to which from a suitable tank or reservoir T is governed by a plurality of suitable valve members 38 and 39, respectively. A plurality of actuating coils for the valves 38 and 39-, respectively, are adapted to be energized during the operation of the system shown in Fig. 2, as more fully described later. The valve 38 is normally closed to exclude fluid pressure from the cylinder 36 but admits pressure thereto whenever the actuating coil 40 is energized; whereas the valve member 39 is normally open-to admit fluid pressure to the cylinder 37 but is adaptedto exhaust pressure therefrom when the actuating coil all is energized. In this way. fluid pressure is normally present in the cylinder 37 and is normally excluded from the cylinder 36, whereby the controller drum is biased to its off position, 'as indicatedby the respective positions of described is concerned, may be set forth as follows: I

When both of the actuating coils 4:0 and 41 are simultaneously energized, fluid pressure is exhausted from the cylinder 37 and is admitted to the cylinder 36 to effect a movement of the controller drum through its various operative positions until the actuating coil 41 is deenergized, when balanced pressure conditions exist in the two cylinders 36 and 37, whereby the controller drum is positively and rapidly brought to rest in any desired position. In the system illustrated in Fig. 2, the operation of the valve member 39 is controlled by a limit switch to automatically effect a stepby-step operation of the controller drum in accordance with the requiredserv'i'ce conditions. To return the controller drum to its off position, it is merely necessary to simultaneously deenergize both actuating coils 40 and 41, whereby fluid pressure is exhausted from the cylinder 36 and is admitted to the cylinder 37.

Reference may now be had to the auxiliary governing system that is shown in Fig. 2

' which comprises the actuating coils of the various main 'circuit switches and of the controllers PKl and PK2; a master controller M'Ql that is adapted to occupy a plurality of positions a, Z) and c in an accelerating direction and a plurality of operative positions a, Z) and c in a regenerative direction; a master reverser MR of a familiar type that is associated in the customary manner with a pair of actuating coils r and f of the maincircuit reversing switch RS; a plurality of electrical interlocking contact members of a familiar type that are associated with, and adapted to be actuated by, the various maincircuit switches in the familiar manner that is illustrated in Fig. 3 in connection with switch SWVZ. Inasmuch as the use of such interlock contact members is old and is well known to those skilled in the art, it is not deemed necessary to illustrate all of the main-circuit switches in conjunction with all of the corresponding interlocking contact members, and it is thought that the illustration of Fig. 3 will be suflicient for the purposes ofthe present specification.

The auxiliary governing "system also comprises a suitable source of energy, such as a battery B, and a pair of actuating coils associated with the change-over switch COS and adapted to electrically control its movements to the accelerating or regenerating position, in accordance with the legends marked upon them. In addition to the series relay and the multiple relay already mentioned and which are adapted to perform circuit functions hereinafter described, a multiple auxiliary relay is also used in connection with the multiple relay, having its actuating coil in series-circuit relation with the auxiliar contact members of the latter across the batterv B.

Assuming thatthe master controller MCI is moved to its final operative position 0, the complete automatic accelerating operation of the system shown may be set forth as follows: 1

A circuit is first established from the positive terminal of the battery B, through conductor 50, control fingers 51 and 52, which arebridged by contact segment 53a of the master controller, conductor 54, contact segment 55 of the master reverser MR in its forward position, conductor 56, contact segment 57 of the reversing switch HS in its forward position, conductors 58, 59, 60, 61 and 62, the actuating coil of the switch LS1, conductors 63 and 64, interlock PK1a, interlock COSAcc., conductors 65, 66' and 67, contact member 68 of the change-over switch COS in its accelerating position, conductor 69, controlfinger 70, contact segments 71 and 7 2 and control finger 7 3 of the master controller, and conductor 7A to the negative terminal B- of the battery B. As soon as the switch LS1 is closed, its actuating circuit is transferred through an interlock LSl-indirectly to the conductor 65 through conductor 6564.

Another circuit is simultaneously established fromconductor 58, through conductor 56a, interlockJ-out, conductor 57 a, interlock MQ-out, the actuating coil of the switch JR, interlock COSAcc., and conductor 58a to the negative conductor 66. The motors are thus connected in seriescircuit relation with the accelerating resistors ARl, AR2 and AR3 across the supply circuit (seevFig. 4). The circuit connections just described correspond to the position a of the master controller, and no fun theracceleration would occur were the master controller not to be moved to a subsequent position.

7 However, when the master controller 001- cupiesits position b or c, the automatic operation' is further continued by the establishment of a circuit from the contact segment 53a ofl the master controller, through a control finger 75, conductor 76, interlock G out, conductor 77 interlock LS1--in, the auxiliary contact members 7 8a and 78 of the limit switches RL and AL, respectively, conductor 7 9, interlock 80COS-Acc., conductor 81, interlock 82LS2'out, conductors 83' and 84, the actuating coil of the switch LS2, conductor 63, interlock LS l-in, and conductor 65 to the negative conduc- 'tor 66.

Another circuitis established at this time from conductor 83, through conductor 85, the actuating coil 40 of the controller PKl, interlock Jout, conductors 86, 87 and 88, interlock PK1a and thence to the negative conductor 66, as already described. Moreover, provided the limit switch -AL has dropped to its lower position, further circuit is established through the auxiliary contact members thereof, as already described, to the conductor 81, whence circuit is completed through interlock-89LS2in, conductors 90, 91 and 9160, contact member 92PK1-(4 to (Z, conductor 92a, interlock 93-JR-in, conductor 93a, interlock 94 SW1out and the actuating coil all of the controller PKl to interlock J-out and conductor 86, as already set forth.

Assoon as the switch LS2 is closed, a holding circuit for its actuating coil is formed to include interlock 82LS2-in and conductor 61a, which is connected to the energized conductor 60.

The two actuating coils of the controller PKl, being thus simultaneously energized, the controller is actuated to its initial operative position I) to bring a contact member 42 of the controller (Fig. 1) into engagement with a plurality of control fingers that are associated with the resistor A112, thereby short-circuiting one section thereof. As soon as the controller reaches its position b, the limit switch will have lifted, thereby temporarily preventing further operation of the controller. The controller Phil is thus moved step-by-step, in accordance with the limit switch AL, to its position 6, thereby gradually excluding the resistors AR2 and A113 from circuit. The circuit connections at this time correspond to the position Z) of the master controller, or, in other words, full-series connection of the motors.

However, with the master controller occupying its position a, a circuit is next established from the contact segment 53a, through control finger 95, conductors 96 and 97, contact member 98-PK1-e to g, interlock COS-Ace, interlock G'out, the actuating coil of the switch J and conductor 99 to the negative conductor 66. The actuating coil of theswitch JR and the actuating coils 40 and ll of the controller PKl are deenergized upon the closure of the switch J by reason of the exclusion from their control circuits of. the respective interlocks J out. The two actuating coils of the controller PKl being thus simultaneously deenergized, the'drum returns to its off-position a. When the limit switch AL has again dropped, a further circuit is completed through its auxiliary contact members to the conductor 90, as already described, and thence through conductor 100, interlock COSAcc. conductor 101, interlock PK1a-,

interlock M2out, conductor 102, interlock J R-out, the parallel-connected actuating coils of the switches M2 and G, conductor 103, interlock COS-Ace, and conductor 104; to conductor 87, whence circuit is completed as already set forth. Upon the closure of the switches M2 and Gr, the circuit of their actuating coils is transferred through interlock M2-in and conductor 101a to conductor 108. The closure of the switch G effects the opening of the-switch J by reason of the exclusion of the interlock G--out from the energizing circuit of its actuating coil. The motors have thus been brought to the initialparallel position by means of the familiar bridging transition method, and the resistors AR2 and AR3 are again actively connected in the circuits of the respective motors.

The opening of the switch J allows the enengization of the actuating coil 4E0 of the controller PKl through interlock J'out, as hereinbefore described. The other actuating coil ll of the controller PKl is also simultaneously energized, from the conductor 91, through conductor 105, interlock JRout and conductor 9364, as already described. The controller PKl is thus successively actuated through its various operative positions in accordance with the limit switch AL, the energization of the actuating coil l1 being continued beyond the position 6 of the controller PKl by reason of the substitution for the contact member 92 of the interlock J Rout.

When the controller PKl reaches its position f, a. contact member 44 (Fig. 1) is adapted to effect the exclusion from circuit of a portion of the main field winding F1, and a contact member 45 is adapted to perform a similar oifice, when the controller reaches its final operative position 9 in connection with the field winding F2. The

. well known field control is thus eflected to produce a further accelerating step of the motors, as will be understood (see Fig. 5).

The regenerative operation of the system will now be described. The general function of the relays respectively marked Series relay, Multiple relay and Multiple auxiliary relay may first be pointed out to advantage, and the specific connections effected by them will be described later in connection with the regenerative operation. However, the use of such relays in a system of control is not of my present invention, but is shown and described and claimed in my co-pending application, Serial No. 71,192, filed Jan. 10, 1916, and assigned to the Westinghouse Electric & Manufacturing Company. The series relay is adapted to act at a relatively low voltage, for example, 200 volts, to efiect the connection of the machines in series relation across the supply circuit, provided the speed of the machine is so low that it would be impossible to elfect regeneration by parallel connection of the machines. On the other hand, the multiple relay andmultiple auxiliary relay in conjunction are adapted to connect the motors in initial parallel-circuit relation across the supply circuit, provided the voltage of each motor is suflicient to individually efi'ect regenerative operation to the" supply circuit. By the use of both the multiple relay and the multiple auxiliary relay in conjunction, the operation of the circuits governed by them is delayed slightly behind the operation of the circuits that are governed by the series relay whereby, in case of relatively low speeds of the momentum-driven machines, the series'relay will act first to efl'ect the series connection of. the machines before the multiple relay has an opportunity to effect its circuit changes. In other Words, if the multiple relays are actuated, although the series relay is of necessity alsooperated, the momentum driven machines are initially connected in parallel-circuit relation; the PK2 drum is then automatically operated, in accordance with the limit switch BL, to efiect a gradual short-circuit of the resistors R1 and R2 as the machine speeds decrease; the. machines are then automatically changed over to series-circuit relation, with the resistors R1 and R2 initially in circuit; and these resistors are then again gradually short-circuited as the speeds of the machines still further decrease. However, in case conditions are such that parallel regenerative operation of the machines is impracticable, the series relay alone acts, whereby the control drum PK2 is immediately moved through positions that correspond to parallel operation of the machines to the initial position that corresponds to the series relation thereof, and the remaining operation of the system is the same as before.

Assuming that conditions are suitable for parallel regenerative operation of the machines; the master controller MO may be first moved to its final operative position 0, whereby a circuit is first established from the positive terminal of the battery B, through the master controller in its position 0 and the master reverser in its forward position, and to the conductor 56a, as described in connection with acceleration, and thence, through conductor 67a, interlocks PK2-a,, PK1 -a, SW2-out and LS1 out, the actuating coil of the change-over switch COS that corresponds to regenerative operation, contact segment 68a of the change-over switch in its accelerating position, conductor 69a, control fingers 7 0a and 73, which are bridged by contact segment 71a of the-master controller, and thus to'the negative terminal of the battery B. The change-over switch COS is thus actuated to its position corresponding to regenerative operation wherein the circuit just described is broken at the contact segment 68a.

58a and 66 and the contact member 6864 of the change-over switch to the battery B, as already described.

The closure of the switch FC effects the inclusion of thefield-magnet winding MFb of the motorgenerator or dynamotor in the circuit thereof. It will be understood that this motor-generator or dynamotor may be employed during acceleration of the main motors for the purpose of supplying energy to the various auxiliaries employed-upon the car, such as the lighting and the control system, if desired, and may also be used to mechanically drive an air-compressor, in ac,- cordance with familiar practice. However, in such a case, ithas been found to be of advantage to increase the field excitation of the motor-generator or dynamotor during regenerative operation of the main machines, and this increased excitation is obtained by the closure of the switch FC as just described.

The closure of the switches SW1 and SW2 effects the connection of the generatorarmature winding G through the resistors R1 and R2, respectively, to the field inagnet windings F1 and F2, as simply illustrated in Fig. 6. r

Another circuit is simultaneously established from conductor 56a, through conductors 108 and 109, contact member PK2-a. to g, conductors 110 and 111, the auxiliary contact members .112 of the multiple auxiliary relay in its upper position, the actuating coil of which has been energized through the closure of the multiple relay, as already mentioned, conductor 113, interlock vCOSReg., conductor 101, thence through the actuating coils of the switches M2 and G, as already set forth, conductor 103, interlock Jout and conductor 104:. to the negative-circuit conductor 66, as hereinbefore described.

A further circuit is established from the master controller, through the actuating coil of the switch LS1, as set forth in connection with the acceleration of the motors, to the interlock PK1a, whence its circuit is completedthrough conductor 114, the auxiliary contact members 115 of the multiple'auxiliary relay in its upper position, conductor 116 and conductor 65a to the negative conductor 66. The momentum-drivenmachines at this time are thus connected in the manner shown in Fig. 7

Another circuit issimultaneously established from the conductor 60, through conductor 118, interlock COS-Reg, conductor 81 and the interlock 82LS2out to the actuating coil of the switch LS2 and thence, through the interlock PK1-a, as already described in connection with the switch LS1. The circuit connections just described correspondto the position a of the master controller, and no further-regenerative operation would occur if the master controller were not moved to one of its subsequent positions. f Y.

Provided that the limit switch BL has dropped to its lower position, circuit is next established from contact segment .53 of the master controller in position b or "a", through control finger 75, conductor 7 6, contact member 119 of the controller PKQ in its off position a, conductor 7 7, interlock LS1in, the auxiliary contact members 7 8a of the limit switch RL, contact segment X of the master controller, conductor 79, interlock COSReg., conductors 120 and 121-, the actuating coils 41 of the PK2 controller, interlock SVV1in and conductor 122 to the negative conductor 166. Both actuating coilsof the PKQcontroller being thus simultaneously energized, a stepby-step movement of the controller, in accordance with the operation of. thelimit switch RL, will occur.

The circuit disposition of the series actua'ting coil of the limit switch BL has already been described, and its purpose pointed out.

lAsa further means of obtaining adesirably constant regenerated current, the limit switch BL is provided with an auxiliary battery-energized actuating coil 0 that is brought into operation in various positions of the controller PK2 to vary thesetting of the switch and ,thus aid in producing a sub"- stantial equalization of thetorques of the several machines and of the regenerated currentsthroughout the regenerating period. For example, it will 'be observed that the coil 0' is connected in circuit in positions 0, d and j and k of the controller PKQI, but is inoperative at. other times. I

The controller PKQ is actuated,,in a stepby-step manner already described, to the po sition, 7 which corresponds to full-parallel relation of the regenerating machines and to position b of the master controller, the

resistors R1 and R2 having beengradually stood. Provided the master controller occupies its position 0, the energization of the actuating coil ll-(PK?) is maintained until the switch Gr opens and theinterlock G-out thus becomes operative, through contact segment 53, control finger 95, conductor 96, control finger 96a, and "contact'segment 119.

As soon as the controller PK2 occupies its position 9 theshort-circuits of the resistors R1 and R2 are removed. Also a control circuit is established from the conductor 56a, through conductor 125, contact member 126 -PK2'g and it, auxiliary contact members 127 of the series relay in its upper Position, the actuating coil of the switch J and conductor 99 to the negative conductor 66. v

In order to prevent a path of relatively low resistance being connected across the supply circuit by the closure of the switch J atlthe time that the other switches, already mentioned, are closed, the transition resistor BJ is employed in seriesscircuit relation with the switchJ. As illustrated in Fig. 1, when .the controller PK2 occupies its position g, the entire resistor RJ is connected in circuit and, in the two succeeding positions it" and 'c", the resistor is gradually short-circuited, the switches M2 and G havingwbeen opened immediately upon closure ofthe. switch J by reason of the exclusion of the interlock J--out from the control circuit of the actuating coils. When these switches have been opened, there is no longer any danger of a short-circuit connection, and, consequently, the resistor RJ may be excluded from circuit.

Moreover, upon the occupation of position .b the controller PK2, contact segment 123 hereof (Fig. l) engages control finger 12-}, whereby the hitherto separated ends of theresistors' R1 and R2 are connected to dispose the resistors in parallel-circuit relat1 on,'1t be ng foundv that a lesser variable circuit resistance is desirable during series rege eration- At this time, therefore, the regenerating machines vare connected 1n series-clrcu t relation, with the parallel-connected resistors R1 and R2 actively vincircui't (see Fig- 8). The further step-by-step automatic 'actuation'o'f the controller PK2 again effects the gradual short-circuit of the resistors R1 and R2 to maintaina substantially constant regenek iated current to a relatively low vehicle P3 Assuming, now that the speed of the mo- Inentum-driven motors is unsuitable for setting up parallel regenerative operatiornbut that the initial voltage induced inthearmatures of the machines through the energization-of their field by the generator armature winding G is equal to 200' volts or any. other predetermined value that is suit able for series regeneration, the operation of the system, upon the actuation of the; master controller to its position c may be set forth as follows:

.The switches FC, SW2 and SW1 are closed and the, actuatingcoil 40 of the controller PK2 is energized, as already related in connection with the multiple regenera tionof'the machines. Simultaneously, another circuit is established from conductor 108, through conductor 109, contact member PK2a to g, conductors 110, auxiliary contact members 126 of the multiple auxiliary relay in its lower position, conductor 129, interlock PK1a and conductors 130 and 121 to the actuating coil 41 of the controller PK2.

The energization of the coil 41 is thus independent of the operation of the limit switch RL, and the controller PK2 is rapidly moved to its positioirh, whereby the circuit is broken at the interlock PK2a-' to g. However, the energization of the ac tuating coil 4L1-(PK2) is maintained as far as position j by reason of the bridging of the auxiliary contact members 78a of the limit switch 'RL by a contact member 117- PK2-g toe", the circuit being otherwise as already described in connection with multiple regeneration. The switches M2 and G are prevented from closing by reason of the exclusion ofthe auxiliary contact me1nbers 112 of the multiple auxiliary relay from the circuit of their actuating coils.

' At the same time, the actuating coil of the switch LS1 is energized from the master controller, in the manner already related, to the conductor 6%, whence circuit is now completed through conductors 88 andl l, auxiliary contact members 132 of the series relay inits upper position, conductor 133, contact-member 134PK2-g' to a, and conductor 135 to the negative conductor 66. The switch LS2 is then closed, as soon as the limit switch RL has dropped to its lower position, through the circuit already traced in connection with the multiple regenera tion of the'machines. The switch J is also brought in as soon as the PK2 controller occupies the position 9, in the manner already described in connection with the transition of the machines from parallel to series relation. The energizing circuit of the actuating coil 41 of the PK2 controller is then transferred through the auxiliary contact members 7860 of the limit switch RL, as hereinbefore described, and the PK2 controller, from that time on, is actuated in accordance with the operation of the limit switch RL, and in exactly the same manner as that set forth in connection with the latter or series portion of the regenerative operation hereinbefore described.

It will be observed that one of the most advantageous features of the automatic system ]L1St described is the combination of means for inherently imparting to the regencrating machines a negative compound characteristic, that is, an inherent decrease of field winding current obtains upon an incipient increase of armature current, and vice versa, and limit-switch controlled means for varying the field excitation of the machines as their speed decreases to maintain a substantially constant regenerated current. The

. governing said advantages of the negative compound characteristic that is provided in the system, such as the instantaneous regulating action and the elimination of relay-controlled or other devices, such as have been used in the prior art, are evident. y,

I have thus provided a relatively simple, effective and reliable system of interlocking and governing circuits for the main-circuit connections that are shown and claimed in the above-identified co-pending application of R. E. Hellmund.

I do not wish to be restricted to the specific circuit connections and arrangement ofparts herein set forth, as various modifications thereof may be effected without departing from the spirit and scope of my invention. I desire, therefore, that only such limitations shall be imposed as are indicated in the appended claims.

I claim. as my invention 1. In a system of control, the combination with asupply circuit, and a plurality of dynamo-electric machines adapted for both acceleration and regeneration, of plural-position, power-operated means for arranging certain circuits in accordance with the one or the other machine operation, a plurality of switching means for acting in selected conjunction with said power-operated means to complete said circuits, a single means for power-operated means and said switching means, and means forpreventing one type of operation of said machines when said power-operated means occupies a non-corresponding position.

2. In a system of control, the combination with a supply circuit, and a plurality of dynamo-electric machines adapted for both acceleration and regeneration, of a pluralposition, electrically-controlled switching device for arranging certain machine circuits in the one or the other position in accordance with the one or the other machine operation, a plurality of electrically-controlled switches for' acting in selected conjunction with said switching device to complete said circuits, a single controller for governing said switching device and said switches, and electrical interlocking means for preventing one type of operation of said machines when said switching device occupies a non-corresponding position.

3. In a system of control, the combination with a. supply circuit, and a plurality of dynamo-electric machines adapted for both acceleration and regeneration, of an auxiliary source of energy, aplural-position, electricallv-controlled switching device for arranging certaincircuits of said machines and of said source in the one or the other position in accordance with the one or'th other machine operation, a plurality of electrically-controlled switches for acting in selected conjunction with said switching deing position, and

vice to complete said circuits, a single controller for governing said switching device and said switches, electrical interlocking means for preventing the establishment of preliminary regenerative circuits when said switclnng device occupies a noncorrespondmeans for preventing regenerative operation when said switching device occupies the proper position unless said source of energy is operative.

4. In a system of control, the combination with a supply circuit, and a plurality of dynamo-electric machines adapted for both acceleration and regeneration, of an auxiliary generating machine for exciting said field windings during regeneration, a plural.- position electrically-controlled switching device for arranging certain circuits of all of said machines in the one or the other posi tion in accordance with the one or the other main-machine operation, a plurality of electrically-controlled switches for acting in selected conjunction with said switchingv device to complete said circuits, a single controller for governing said switching device and said switches, electrical interlocking means associated with said switching device for preventing the establishmentof preliminary fieldexcitation circuits when the switching device occupies a non-corresponding position, and independent means for preventing the regenerative connection of the main: machines to the supply circuit when said switching device occupies the proper position unless said generator is o'peratively running.

5. In a system of control, the combination with a supply circuit, and a "plurality of dynamo-electric machines adapted for both acceleration and regeneration, of a plural-position, electrically-controlled switching device for arranging certain machine circuits in the one or the other position in accordance with the one or the other machine operation, a plurality of supply-cir cuit-connecting switches, an accelerating resistor adapted to be short-circuited by the simultaneous closure of said switches, means for successively closing said switches during the initial accelerating period, and means associated with said switching device for efiecting the simultaneous closure of said switches during the initial. regenerative period.

6. In a series-parallel system of control, the combination with a plurality of dynamoelectric machines severally having armatures and plural-section field-magnet windings, of a plurality of main-circuit controlling switches including certain switches that are used during only series or parallel machine operation, a plurality of accelerating resistors, a step-by-step means actuated in accordance with predetermined main-circuit conditions for gradually excluding said'resistors from circuit during both series and parallel machine operation, and interlocking means associated with said step-by-step means and with one of said switches that is used during only series machineroperation for effecting the exclusion from circuit of certain sections of said field windings only after the machines are disposed in full parallel relation.

7. In a series-parallel system of control, the combination with a plurality of dynamoelectric machines adapted for both acceleration and regeneration, of a plurality of main-circuitcontrolling switches, a plurality of accelerating resistors, step-by-step means actuated in accordance with predetermined main-circuit current conditions for gradually excluding said resistors from circuit during both series and parallel acceleration, and means partially dependent upon the closure of a certain switch during initial regeneration for effecting the actuation of said step-by-step means to a predetermined position irrespective of main-circuit current conditions.

8. In a series-parallel system of control, the combination with a plurality of dynamoelectric machines adapted for both acceleration and regeneration and severally having armatures and plural-section field-magnet windings, of a plurality of main-circuit-controlling switches, including certain switches that are used during only series or parallel acceleration or regeneration, a plurality of accelerating resistors, step-by-step means actuated in accordance with predetermined main-circuit current conditions for gradually excluding said resistors from circuit during both series and parallel acceleration, interlocking means associated with said stepby-step means and with certain of said switches that are respectively used during series acceleration and regeneration for effecting the exclusion from circuit of certain sections of said field windings after the machines are disposed in full parallel accelerating relation, and interlocking means partially dependent upon the closure of a certain switch during initial regeneration for effecting the actuation of said step-by-step means to a position wherein said resistors are excluded from circuit and full field windings are included in circuit, irrespective of main-circuit current conditions.

9. In a series-parallel system of control, the combination with a plurality of dynamo-electric machines adapted for both acceleration and regeneration and severally having armatures and plural-sectionfieldmagnet windings, of a plurality of maincircuit-controlling switches, including certain switches that are used during only series or parallel acceleration or regeneration, a plurality of accelerating resistors, step-by-step means actuated in accordance with predetermined main-circuit-current conditions for gradually excluding said resistors from circuit during both seriesand parallel acceleration, interlocking means associated with said step-by-step means and with certain of said switches that are respectively used durin series acceleration and regeneration for efi ecting the exclusion from circuit of certain sections of said field windings after the machines are disposed in full parallel accelerating relation, a plural-position, electrically:controlled switching device for arranging certain machine circuits in the one or the other position in accordance with the desired machine operation, and interlocking means associated with said switching device and with one of said switches for effecting the actuation of said step-by-step means during initial regeneration to a position wherein said resistors are excluded from circuit and full field windings are included in circuit, irrespective of main-circuit current conditions.

10. In a parallel-series system of regenerative control, the combination with a supply circuit, and a plurality of dynamo-electric machines adapted for both acceleration and regeneration, of a plurality of fieldregulating resistors, step-by-step means for gradually excluding said resistors from circuit during both parallel and series regeneration in accordance with predetermined main circuit current conditions, contact means associated with said step-by-step means for effecting the actuation thereof-independently under predetermined conditions, and means for permitting said independent actuation only when said machines are connected in series relation.

11. In a parallel-series system of regenerative control, the combination with a supply-circuit, and a plurality of dynamo-electric machines adapted for both acceleration and regeneration, of a plurality of main-circuit-controlling switches including switches that are used only during parallel operation, a plurality of field-regulating re-, sistors, step-bystep means for gradually excluding said resistors from circuit during both parallel and seriesregeneration in accordance with predetermined main-circuitcurrent conditions, contact means associated with said step-by-step means, for effecting the independent actuation thereof through a plurality of transition positions, and interlocking means for permitting said independent actuation only when certain of said switches that correspond to parallel operation have been opened.

12. In a parallel-series system of regeneratiy e control, the combination with a supply-circuit, and a plurality of dynamo-electric machines adapted for both acceleration and regeneration, of a plurality of main-circuitecontrolling switches including an auxiliary field-magnet switches that are used only duringparallel operation, a plurality of field-regulating resistors, a step-by-step controller for gradually excluding said resistors from circuit during both parallel and series regeneration, a limit switch for governing the actuation of said controller in accordance with predetermined main-circuit current conditions, contact means associated with said. step-bystep controller for short-circuiting said limit switch through a plurality of transition positions, and interlocking means for permitting said short-circuiting only when certain of said switches that correspond to parallel operation have been opened.

13. In a system of control, the combination with a supply circuit, and a plurality of dynamo-electric machines adapted for both acceleration and regeneration and severally having armatures and field-magnet windings, of an auxiliary generating armature for exciting said main field windings durin regeneration, a second motor armature or driving said generating armature,

winding for said auxiliary armatures, means for establishing preliminary field-excitation regenerative circuits, and means dependent upon such establishment for varying the active value of said auxiliary field-magnet windings.

14. In a system of control, the combination with a supply circuit, and a plurality of dynamo-electric machines adapted for both acceleration and regeneration and severally having armatures and field-magnet windings, of an auxiliary generating arma- Gopies or this patent may be obtained for five cents each, by addressing the ture for exciting said main field windings during regeneration, a second motor armature for driving said generating armature, an auxiliary plural-section series-type fieldmagnet winding for said auxiliary armatures, means for establishing preliminary main-field-excitation regenerative circuits, and means dependent upon such establishment for including an additional section of said auxiliary field-magnet winding in circuit.

15. In a system of control, the combination with a supply circuit, and a plurality of dynamo-electric machines adapted for both acceleration and regeneration and sev erally having armatures and field-magnet windings, of an auxiliary generating armature for exciting said main field windings during regeneration, a second motor armature for driving said generating armature, an auxiliary plural-section series-type fieldmagnet winding for'said auxiliary armature, and a plural-position switching device for arranging certain circuits of all the dynamo-electric machines in the one or the other position in accordance with the desired main-machine operation, a certain additional section of said auxiliary field-magnet winding loeing included in circuit by said switching device under preliminary regenerative circuit conditions.

In testimony whereof, I have hereunto subscribed my name this 31st day of Dec, 1915.

ARTHUR J. HALL.

Commissioner of Patents,

Washington, D. 0. 

